Thank you for the response, it is 0.293 unfired and the same fired. Im sorry I should have put that on the post. Its crazy how it measures the same, but the bullet does slide in a fired case easily.
So I bought a used custom built 260 Remington, the person I bought it from knows nothing about the rifle. I considered having it re- barrelled to a 6 br, but have never owned a 260 I thought I would at least give it a try. It has a bat action and the barrel is unknown. I bought new Lapua brass...